Mini-Drill Quill Feed Shaft Gear diameter missing

Here's an e-mail I received from Don Holloway on Dec 27, 2011:

----------------------

Hi
I purchased plans for the precision mini drill press a while back and want to start to build soon.
The only thing that I don't see is the OD for the quill feed shaft gear.
Do you know what the OD of the gear should be?

Thanks and the best to you folks in the new year.

----------------------

My reply:

Don,

Good question.  Nobody has asked me that before, and I did not realize it was missing.  Unfortunately, Dad passed away over two years ago so I can't ask him, and his prototype does not have this gear exposed for me to measure it.

Would the pitch and angle of the gear teeth determine the diameter?  I'm not a machinist, so maybe I'm all wet in that theory.

I will post your question on our user forum - perhaps some other builders will be able to assist.  If not, I guess hold off on this part as long as possible, then perhaps the diameter can be surmised by the distance from it's shaft and the position of the quill - ???

Allen

--------------------

If anyone can help answer this more definitively, it would be appreciated!

Thx...

Ken Morris's Mini-Drill motor

Ken sent me this e-mail on Nov 19th:

--------------------------------------------

"I used an electric motor from a Beam central vac powerbrush.  To control the speed I used  a router speed control. Motor cost is about $30.00. Mounting is no problem but the speed control is necessary. Ken"

I asked for verification of the drill used on - Micro Drill or Mini Drill.  He replied:

"HI Allen.  RE: drill press motor. The motor fits the mini drill press and is an exact fit. Brackets can be made easily and the shaft is .250. It is a 120 v motor and once again this motor is fitted into the beater head of the Beam central vac.  I use a router speed control to monitor the speed. I have more pictures. Thanks, Ken"

Electric motor sources

I get e-mails from drill plans purchasers wanting to know where to get the electric motors to run the Mini Drill and Micro Drill projects.  It would seem that some of the sources Dad mentioned in the plans are no longer available.  Those of you who found a motor, can you share with us where you got it? (if they are still available) 

I went to Mendelson's in Dayton (one of Dad's favorite places to search for various items) to look for any surplus they might have, and did not find anything matching Dad's specs, as most of the motors they had there are AC or stepper motors.

For Micro-Drill, Dad calls for: 12 volt DC, 1-1/4" long x 7/8" diameter with a 1/8" diameter shaft.  If you can't keep the motor from turning by pressing on the shaft with your index finger and thumb at 6 volts, then it should have enough torque.

For Mini-Drill, Dad calls for: 24-28 volts DC, min 3000 RPM, permanent magnet, ball bearings, 2-1/4" to 2-1/2" diameter and a 1/4" or 5/16" diameter shaft.

Again, if anyone knows of a source for these motors that match these specs, or if you used a motor with different specifications with good results, please reply here, or send me an e-mail to allen@outpostenterprises.com.

Thanks!

-------------------------------------------------------

A builder responds:

"I found a good motor for the mini drill from Zoro on the internet. You can power it with a lap-top type 24v 10 amp supply, but you will need to create a starting device. The resistance before starting is 1.2 Ohms which will draw a 20 Amp surge when starting, looking like a short to the power supply. One way is to put the switch on the ac line side so the power supply and the motor ramp up together. Better to add a 2-3 Ohm 5W resistor shorted out with a relay after a second or two.

Or you can get a big power supply and put it in a box, resulting in something the size of a bread box. Not cool.

The motor I got from Zoro is their # G1958126. 24 V, 6 Amp, which fits nicely."